Thread protector



Sept. 26, 1950 H. A." UNKE THREAD PROTECTOR Filed May 5, 1945 l IN VEN TOR.

Lm n uw E K m. A ,M W

Patented Sept. 26, 1950 UNITED STATES ATENT GFFIC THREAD PRGTECTOR Herman A. Unke, Parma Heights, Ohio Application May 5, 1945, Serial No. 592,187

(Cl. 13S-96) 4 Claims.

This invention relates to protectors for threaded pipe-ends and the like and, as one of its objects, aims to provide an improved device of this kind which can be economically produced and which Will protect the threaded end of the member on which it is intended to be used, in a more complete and satisfactory manner than has been done heretofore.

Another object of this invention is to provide an improved thread protector which can be readily applied to or removed from the threaded end of` a pipe or the like but which, nevertheless, is not likely to be jarred loose and will protect the threads without coming into metallic contact therewith.

A further object of the present invention is to provide an improved thread protector of this character in which a metal shell has a non-metallic liner therein for engagement with the threads of a pipe-end or the like and wherein the liner is made of a waterproofed fibrous material and forms a seal with portions ofthe pipe-end so as to exclude water and other foreign matter from the threads.

Still another object of this invention ist` provide an improved thread protector of the character mentioned, which is especially suitable for pipe-ends or the like having a relatively long threaded portion and wherein the fibrous liner extends a substantial distance beyond the metal Fig. 1 is an elevational view of a pipe end have ing the improved thread protector thereon;

Fig. 2 is a longitudinal sectional view taken through the protector;

Fig. 3 is a transverse sectional view of the protector taken on line 3-3 of Fig. 2; and

Fig. 4 is a partial longitudinal sectional View on a larger scale, further illustrating the con'- struction of the protector and the cooperation of the protector with the threaded member.

More detailed reference will now be made lto the drawing in describing the improved thread protector Illv which is here shown as applied to the threaded end Il of a pipe or conduit member I2. As indicated above the protectorl is especially suitable for use on a pipe-end or the like having a relatively long threaded portion and the threaded portion II of the pipe I2 is accordingly shown in the drawing as being such a relatively long portion. This relatively long portion having the thread I3 thereon is here shown as being a tapered portion although the protector I0 vcan also be usedY on substantially straight threaded portions.

The protector IE! comprises a hollow metal shell Ill and a non-metallic liner I5 engaging in the shell and extending coaxially thereof. The metal shell it has a substantially cylindrical sleeve portion I6 which is open at one end thereof and at its other end is-provided with an integral transverse wall portion i'I extending substantially normal to the axis of the sleeve portion. The end wall can have an opening therein .or can be imperforate as here shown. The shell I4 can be constructed by any suitable manufacturing operation such as by drawing, or stamping the same from sheet metalof'appropriate thickness. The non-metallic liner I5 may be formed of paper or other Afibrous material and comprises a Vrelatively `stili substantially cylindrical sleevey which extends coaxially of the metal shell I4 and engages in the sleeve portion I5 thereof. This non-metallic liner may be obtained by cutting a section of appropriate length from iibrous or paper tubing of appropriate diameter and wall thickness.v In the protector I0 the liner I5 extends for substantially the full length of the metal sleeve portion It and a'portion Ilia of the liner extends outside the metal sleeve portion for a substantial distance, depending'upon the length of the threaded portion to be covered and protected. In this instance the projecting portion I5a of the liner is approximately as long as the metal sleeve portion I6 and, in all cases, should .not only be long enough to cover all of the threads but should also extend beyond the threads and overlap the adjacent unthreaded portion of the pipe I2. This overlap is important because at this point a tight annular engagement is obtained ,which assists in retaining the pro- .tector on the pipe and also forms a continuous annular seal or closure as indicated at I5b which prevents water and other foreign matter from rentering between the pipe and liner and damaging the thread I3.

The liner I5 is assembledinto the metalshell tween the metal sleeve portion I6 and the nonmetallic liner I by which the liner is held against withdrawal from the metal sleeve portion and is locked to the metal shell for rotation therewith. At corresponding circumferentially spaced points the liner is deected inwardly by the indentations I8 thus providing internal projections or areas I9 on the liner which provide spaced points of engagement with the thread I3 of the pipeend II when the protector is applied thereto. These internal projections I9 will accommodate themselves to any taper angle on the pipe and by their annularly spaced engagement with the pipe-end they center the metal shell I4 thereon.

The paper or brous tube from which the nonmetallic liner I5 is formed should preferably be initially treated or impregnated with a waterproofing material such as paraflin, asphalt or any other material suitable for this purpose. After the liner I5 has been assembled into the sleeve portion I6 of metal shell I4 as above explained, the liner is provided with an external coating or layer of waterproofing material as shown in Fig. 4. This external coating may be a layer of paraflin, asphalt or any other material suitable for this purpose. This external coating 20 may vbe applied to the liner I5 in any suitable way such as by dipping the opend end of the protector I0 into a bath of the waterproofing material and spraying or squirting some of the bath inside of the liner and metal shell.

' f Fig. 4 of the drawing shows the protector I0 "after the external coating 29 of waterproofing material has been applied and, as will be seen from this view, this coating extends continuously over the outer surface ofthe projecting portion I 5a of the liner and also extends around the free -end of the liner and over the entire inner surface assist in forming the important annular seal I5b at this point and renders this seal capable of excluding water and other damaging liquid or matter. The coating also cooperates with the open end or edge of the metal sleeve portion I9 to form an annular seal at this point as is indicated at 2| for preventing rain or other liquid from soaking into the protector between the metal shell and the non-metallic liner I5. Likewise, the coating material 2i] forms a similar annular seal between the liner and the transverse Wall Il as is indicated at 22.

An important advantage of the present construction is that it is not necessary to construct the metal shell I4 with its sleeve portion I6 of a length to completely cover the threaded portion of the pipe because suilicient protection for the inner end of the threaded portion of the pipe will be provided by the non-metallic liner I5. If the sleeve of the metal shell were to be Ymade as long or longer than the threaded portion to be protected, the metal shell would be of an increased weight and the cost of manufacture would be correspondingly increased. Since the liner I5 is formed of paper or other inexpensive fibrous material it can be extended in length the pipe. Fewer and less damaging blows are received by the threads located inwardly from the extreme end of the pipe, but nevertheless, it is necessary to provide a covering for such inwardly located threads to protect them from blows and from rain or other foreign matter. In my improved protector IIJ the metal shell I4 will cover the extreme end of the pipe and will receive and absorb the more numerous and severe blows mentioned above. By providing the extended liner portion I5a having the solidied waterproofing coating 20 thereon, the threads lying inwardly of the metal shell will be covered and amply protected against blows and sealed against the entry of rain and other foreign matter.

The protector I0 can be applied to the threaded pipe-end I I by slipping the protector in telescoping relation over the pipe-end as far as possible by a simple coaxial movement, that is until the internal projections I 9 engage the thread I3, and then screwing the protector onto the pipe by relative rotation therebetween. During this relative rotary movement the thread I3 of the pipe will cut a corresponding thread groove in the internal projections I9. This will cause the protector to be screwed fully and rmly onto the pipe with the inner end of the liner wedged or pushed tightly onto the adjacent unthreaded portion of the pipe. In this fully applied position of the protector, as shown in the drawing, the projecting portion I5a of the liner I4 will fully cover and protect the threads which are not covered by the metal sleeve portion I6 and the tight closure and seal I5b will be established and maintained. When the protector is to be removed from the pipe a reverse relative rotation between the pipe and protector causes the latter to be backed part way off the threaded section. After a sulicient number of revolutions the internal projections I9 will be sufliciently disengaged from the thread I3 to permit the protector to be completely re- -moved from the pipe end by a simple relative axial movement.

As shown in the drawing, the internal projections I 9 of the liner I5 are elongated axially of the protector I0 and each has a relatively long, gradually sloping portion I9a extending in an inward axial direction from the high point or apex of the projection and a relatively short, steeply sloping portion I9b extending axially in the opposite direction 0r outwardly from such high point or apex. These inwardly extending gradually sloping portions I9a enable the projections I9 to more readily adapt themselves to the taper angle of the threaded portion of the particular pipe-end to which the protector is applied and, since they are of a length to extend across and engage several thread ridges, they will provide strong holding engagement for retaining the protector on the threaded pipeend. These gradually sloping portions I9a also serve the important function of enabling the protector to be more easily applied to the threaded portion of the pipe and, in some cases, make vit possible to satisfactorily apply the protector to a threaded pipe-end by only a simple straight axial movement instead of by screwing the protector onto the pipe-end. Any tendency for the protector to be accidently pushed axially off the threaded pipe-end will cause the steeply sloping portions I9b to scrape over the thread ridges and, since the steep slope of these portions prevent them from readily passing over the thread ridges, these portions will effectively resist such esagero 4acc'id ental Outward or loosening movement V:of

ithe protector.

Vlroln the foregoing description and the accompanying Vdrawing it will now be readily under- Astood that the present invention provides an imconsiderably greater than that of the metal shell it is possible to provide full protection for a pipe-end'h'aving a relatively long threaded section vvithout incurring the additional cost which tWot.1`l`c'1l".l; e involved if the protector were constructed 'with a metal sleeve of a lengthto fully covferthe threaded section.' Additionally it will beseen that the improved construction provides fa protector Which'will nt various different ta- 'pe'rs and'that in applying the protector to a pipeend, thread grooves will readily be cut in the liner and that the liner or free end of the liner will be firmly pushed over the adjacent unthreaded portion to form a tight closure and seal.

Although the improved thread protector of the present invention has been illustrated and described herein in considerable detail it will be understood, of course, that the invention is not to be regarded as being limited correspondingly in scope but includes all changes and modications coming within the spirit of the invention and the scope of the appended claims. l

Having thus described my invention, I claim: l. A thread protector for a threaded pipe-end or the like having a tapered relatively long threaded portion and an adjacent cylindrical unthreaded portion, comprising a metal shell having a substantially cylindrical sleeve portion which is open at its inner end and is provided at its outer end with an integral transverse Wall portion, said sleeve portion being shorter in length than said threaded portion, 'and a substantially cylindrical liner of brous material in said sleeve portion and extending for substantially the full length of the latter, said liner being of a length such that it projects out of said sleeve portion for a distance suincient to cover all of the threads of the pipe-end lying beyond the sleeve portion of the metal shell and to grippingly overlap said adjacent cylindrical unthreaded portion, said sleeve portion having circumferentially spaced areas indented into said liner and said liner having corresponding circumferentially spaced internal projections of said sleeve portion and liner being located adjacent the outer end of the protector so as to center said outer end on the tapered threaded portion of said pipe-end While the inner end of the liner grippingly engages said unthreaded portion.

2. A thread protector for a threaded pipe-end or the like having a tapered relatively long threaded portion and an adjacent cylindrical unthreaded portion, comprising a metal shell having a substantially cylindrical sleeve portion which is open at its inner end and is provided at its outer end with an integral transverse Wall portion, said sleeve portion being shorter in length than said threaded portion, a substantially cylindrical liner in said sleeve portion and extending for substantially the full length of the latter, said liner being 1 formed of fibrous material impregnated with waterproofing substance and being of a length such Cil B that it projectsout ofsaid sleeve portion for a Adistance suiiicient to cover all of the threads of `the pipe-end lying beyond the sleeve portion of zthe metal shell and to grippingly overlap said adjacent cylindrical unthreaded portion, said l.sleeye portion having circumferentially spaced Vareasindented into said liner and said liner hav- .ing corresponding circumferentially spaced internal projections engageable with the threads of said pipe-end, and an outer layer of Waterproong v:material adhering' to said liner and forming a seal :between the liner and Vmetal shell and also be- `t leen the liner and said threaded and unthreaded ip "tions `of the pipe-end when the protector is lapplied' thereto,y said circumferentially spaced areas and internal projections of said sleeve portion and liner being located adjacent the outer rend of the protector so as to center said outer end ,on the tapered threaded portion of said pipeend While the inner end of the liner grippingly engages said unthreaded portion.

3. A thread protector for a threaded pipe-end or the like having a tapered relatively long threaded portion and an adjacent cylindrical unthreaded portion, comprising a metal shell having a substantially cylindrical sleeve portion which is open at its inner end and is provided at its projections engageable with the threads of said pipe-end,l said circumferentially spaced areas and internal outer end with an integral transverse wall portion, said sleeve portion being shorter in length than said threaded portion, and a substantially cylindrical liner of fibrous material in said sleeve portion'and extending for substantially the full length of the latter, said liner being of a length such that it projects out of said sleeve portion for a distance sufficient to cover all of the threads of the'pipe-end lying beyond the sleeve portion of the metal shell and to grippingly overlap said adjacent cylindrical unthreaded portion, said sleeve portion having circumferentially spaced lugs indented into said liner and providing an interlock between said metal shell and liner and said liner having corresponding circumferentially spaced axially extending internal projections engageable with the threads of said pipe-end, said projections having axially enlarging tapered portions extending tovvard the outer and inner ends respectively of said liner and of which the outwardly extending tapered portion has a relatively steep slope taper and the inwardly extending tapered portion has a gradually sloping taper and is of a length to extend across several thread ridges of said pipe-end, said circumferentially spaced lugs and internal projections of said sleeve portion and liner being located adjacent the outer end of the protector so as to center said outer end on the tapered threaded portion of said pipeend While the inner end of the liner grippingly engages said unthreaded portion.

4. A thread protector for a threaded pipe-end or the like having a tapered relatively long threaded portion and an adjacent cylindrical unthreaded portion, comprising a metal shell having a substantially cylindrical sleeve portion which is open at its inner end and is provided at its outer end with an integral transverse Wall portion, said sleeve portion being shorter in length than said threaded portiony a substantially cylindrical liner in said sleeve portion and extending for substantially the fun length of the latter, said liner being formed of brous material impregnated with waterprooiiing substance and being of a length such that it projects out of said sleeve portion for a distance suflicient to cover all of the threads of the pipe-end lying beyond the sleeve portion of the metal shell and to grippingly overlap said 7 adjacent cylindrical runthreadecl portion, said sleeve portion having circumferentially spaced lugs indented into said liner and providing an interlock between said metal shell and liner and said liner having corresponding circumferentially spaced axially extending internal projections engageable with the threads of said pipe-end, said projections having axially enlarging tapered portions extending toward the outer and inner ends respectively of said liner and of which the outwardly extending tapered portion has a relatively steep slope taper and the inwardly extending tapered portion has a gradually sloping taper and is of a length to extend across several thread ridges of said pipe-end, and an outer layer of waterproofing material adhering to said liner and forming a seal between the liner and metal shell :and also between the liner and said threaded and unthreaded portions of the pipe-end when the protector is applied thereto, said circumferentially spaced lugs and internal projections of said sleeve portion and liner being located adjacent the outer end of the protector so as to center said outerend on the tapered threaded portion of said pipe-end while the inner end of the liner grippingly engages said unthreaded portion.

HERMAN A. UNKE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

